A piece of furniture often comprises structural elements, such as various kinds of beams, which are joined together to form a furniture frame. The furniture frame may be visible, such as in the case of e.g. a typical storage shelf. The furniture frame may also be partly or completely hidden by various functional or design elements, as is typically the case for e.g. an upholstered sofa. There is a need for a furniture frame system which is easy to assemble, and which provides a high mechanical strength.